Method of assembling a switch by the use of an aligning pin

ABSTRACT

A combined potentiometer and switching structure including wiper contacts fixed to a shaft and having contacting engagement with an annular resistor and a pair of switching rings. The wiper contacts are located coincident, or in phase relation. The switching rings are each provided with an interrupted area, such areas are located in an arc complemental to the arc of the resistor and are circumferentially spaced apart a distance not greater than the length of the resistor contacting surface whereby, during rotation of the shafts, circuits connected to the switch rings are opened at different positions with respect to the resistor wiping contact. Alignment openings in the rings accommodate a pin to permit proper positioning of the rings relative to one another and also provide a passage for a conductor upon removal of the pin once the rings are properly positioned and secured against displacement.

I United States Patent 1 1 [111 3,724,067 Tygard et al. 1451 Apr. 3,1973 |54| METHOD OF ASSEMBLING A SWITCH 2.002.054 7/l96l Nelson ct ill"z t/s97 x BY E E OF N ALIGNING pm 3,330,031 711%? Rcdigcr c1 I...29/.WR [75] inventors: Charles M. Tygard; James H. P

. rlmary Exammer-John F. Campbell gzg both of west Covma AssistantExaminerRobert W. Church Attorney--l-larry G. Martin, Jr. and 1. RaymondCur- [73] Assignee: Spectrol Electronics Corporation, tin

City of Industry, Calif. 22 Filed: June 1,1970 [57] ABSTRACT A combinedpotentiometer and switching structure in- [211 Appl 54045 cluding wipercontacts fixed to a shaft and having con- Rdated Application Datatacting engagement with an annular resistor and a pair of switchingrings. The wiper contacts are located [62] gg' g May 1969 coincident, orin phase relation. The switching rings are each provided with aninterrupted area, such areas are located in an arc complemental to thearc of the [52] resistor and are circumferentially spaced apart a I I200/1/68 distance not greater than the length of the resistor contactingsurface whereby, during rotation of the E2 g g ig i shafts, circuitsconnected to the switch rings are 0 455:5 5 opened at differentpositions with respect to the re 2007168 sistor wiping contact.Alignment openings in the rings accommodate a pin to permit properpositioning of the rings relative to one another and also provide a [56]References Cited passage for a conductor upon removal of the pin onceUNITED STATES PATENTS the rings are properly positioned and securedagainst displacement. 2,502,252 3/1950 Faile ..339/8 PB 2,917,64312/1959 Mihanowich ..3l0/42 2 Claims, 6 Drawing Figures PATENTEBAPRSI975 3.724.067

SHEET 1 OF 2 INVENTORS CHARLES M. TYGARD JAMES H. CAMERON ATTORNEYPATENTEDAPRB ma 3.724.067

SHEET 2 [IF 2 INVENTORS CHARLES M. TYGARD JAMES H. CAMERON ATTORNEY OfAssembly" now issued as US. Letters Pat. No. 3,585,562.

BACKGROUND OF THE INVENTION cessible locations may be readily connectedto the switch units is needed.

SUMMARY OF THE INVENTION This invention has to do with a combinedpotentiometer and circuit switching structure. The potentiometer is ofthe conventional annular type having a circular contacting surfaceengaged by a wiping contact fixed to a shaft. A second wiper contact isaffixed to the shaft and is phased with the resistor wiper contact. Thissecond contact engages a pair of conducting switch rings. A circuit isformed from the second wiper contact through each of the switch rings.The switch rings are formed with interrupted areas whereby, at differentpositions of the resistor wiper contact, the

switching circuits are opened.

More particularly, the invention is directed to a structural arrangementwhich is economical to manufacture and convenient to assemble to producea device having very small overall dimensions.

In addition, the invention relates to a unique method of assembling theswitch rings in the switch insulator whereby welding of electrical leadsto the switch rings may be easily accomplished.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of astructure embodying our invention;

FIG. 2 is an end elevation looking to the right, FIG.

FIG. 3 is an enlarged sectional view taken on a line corresponding toline 33, FIG. 2.

FIG. 4 is a sectional view taken on line 44, FIG. 3;

FIG. 5 is an exploded view of the switch rings and resistor illustratingthe orientation of such parts; and

FIG. 6 is a schematic diagram illustrating an arrangement of theresistor and switching rings.

DESCRIPTION OF THE PREFERRED EMBODIMENT The apparatus consists of acasing having sections 10, 11. The section 10 is formed with an end wall12 having an inwardly extending cylindrical hub 13. The hub 13 isprovided with a central aperture forming a 2 bearing in which anenlarged portion 14 of an actuating shaft 15 is joumaled.

The casing section 11 is provided with a discoidal closure 16 which isformed with a central aperture arranged in axial alignment with theaperture in the hub 13 and forming a second bearing for the shaft 15.The end member 16 is attached to the section 11 by a clamp ring 17.

A resistor 18 of substantially annular configuration is fixedly mountedin the section 1 1. The inner surface 20 of the resistor is a contactsurface over which a wiper contact 21 is moved. The contact 21 is fixedon one end of an arcuate spring member 22, the opposite end of which isfixed to an arm 23 which, in turn, is fixedly secured to a sleeve 25 ofinsulating material fixedly secured to the shaft 15. A collector ring 27is attached in conductive relation to the arm 23 and is connected to aterminal 28 by a brush 30.

The casing section 10 is formed at its inner end with a cylindricalflange 33 formed with an annular shoulder 34. The casing 11 is formedwith a circular flange 35 snugly engaging the flange 33 and abuttingagainst the shoulder 34. The sections are held together by a clamp ring37.

A pair of switching rings 38, 40 are fixedly mounted in the flange 33 ofthe casing section 10. In the arrangement disclosed, the switching ringsare mounted in an annular insulation member 41, fixedly mounted in theflange 33 and having a flange or central rib 43 extending radiallyinwardly between the switch rings 38, 40. The inner contacting surfacesof the switch rings are engaged by a wiper contact 45 fixed on one endof an arcuate leaf spring member 46, the opposite end of which is fixedto an arm 47 which, in turn, is fixed to the sleeve 25. A collectingring 50 is fixed in conducting relation to the arm 47, and is connectedto a terminal 53 by a brush S4. The collector rings 27, 50 are separatedby a ring of insulating material 55.

The contacting surface 20 of the resistor 18 extends circumferentiallyless than 360- in the structure shown about 325. The switching rings 38,40 are each formed with an interrupted area in their inner contactingsurfaces. For economy in manufacture, these interrupted areas arepreferably in the form of a notch 58 in ring 38, and a notch 60 in ring40. The switch rings 38, 40 are fixed in the insulating member 41 withthe notches 58, 60 spaced apart circumferentially a distance less thanthe circumferential extent of the effective contacting surface 20 of theresistor 18. It will be apparent rings 38 and 40 are duplicate parts. Toobtain the relationship shown in FIG. 5, it is only necessary to invertone of the rings through an angle of 180.

The switch ring 40 is connected to a terminal by wire 71 convenientlyextended through the apertures 63, 64 in the switching rings and member41, see FIG. 3. The switching ring 38 is connected to a terminal 72 bywire 73. One end of the resistor 18 is connected to a terminal 75 bywire 76. Accordingly, a switching circuit is established from terminal53 to terminal 70 through switching ring 40, and a second switchingcircuit is established through terminal 53 and terminal 72 throughswitch ring 38.

To provide for convenience in assembling the switch rings with theinterrupted areas in the desired phase relation, the rings are formedwith through apertures 63. The member 41 is formed with a throughaperture 63 in the flange or central n'b 43. The apertures 63, 64 arealigned and a pin is extended through the apertures. The rings arepressed into the member 41, or otherwise secured therein, and the member41 is pressed or otherwise secured as by applying adhesive material tothe rings prior to the insertion of the pins, in the section 10. Thealignment pin is then removed and the wire 71 is run through theapertures and fixed to the ring 40. The sections .10, 11 are orientedand fixedly clamped together by the band 37.

in FIG. 6, the interrupted areas in the rings 38, 40 are indicated at58, 60 and as being located coincident with the ends of the resistor 18.The wiper contacts 21, 45 are fixed in phase relation, see also FIG. 4.Accordingly, when the resistor wiper 21 is positioned at the right endof the resistor, the contact 45 is in register with the notch 58 in theswitching ring 39. When the resistor wiper has been moved to the leftend of the resistor, the contact 45 is in registration with the notch 60in the switching ring 40. At intermediate positions of the wipercontacts, both switching circuits are energized.

It will be apparent that the interrupted areas of the switching meansmay be phased to provide interruption of the switching circuits atvarious preselected positions of the resistor wiper contact 21.

While we have described a preferred embodiment of our invention, it isto be understood the invention is not limited thereto since it may beotherwise embodied within the scope of the following claims.

We claim:

1. The method of uniting a pair of switch rings to an annular insulatingsupport member having a central projection forming a rib portion andthereafter assembling the united parts in a housing containing terminalelements having conductor leads depending therefrom comprising the stepsof:

a. providing openings through the rings and rib portion of theinsulating support member;

b. supplying adhesive to the parts of the ring in engagement with thesupport member;

c. arranging the parts with an adhesive coated switch ring contiguouseach side of the rib portion so the openings define a passageway and theswitch rings have a predetermined position relative to one another andto the support member;

d. inserting a pin through said passageway to retain the parts againstrelative movement while the adhesive acquires a set and permanentlysecures the switch rings to the support member;

e. removing the pin and thereafter feeding the free end of the one ofsaid conductor leads through the passageway for connection to one ofsaid rings;

f. securing the free end of a second of said conductor leads to theother ring; and

g. slidably securing the subassembly comprising the switch rings withleads attached and insulating support member into said housing.

2. The method of uniting a pair of switch rings to an annular insulatingsupport member having a central projection forming a rib portion andthereafter assembling the united parts in a housing containing terminalelements having conductor leads depending therefrom comprisingthe stepsof:

a. provl mg openings through the rings and nb portion of the insulatingsupport member;

b. arranging the parts with the switch ring contiguous each side of therib portion so the openings define a passageway and the switch ringshave a predetermined position relative to one another and to the supportmember;

c. inserting a pin through said passageway to retain the parts againstrelative movement to assure proper alignment of die parts;

d. removing the pin and thereafter feeding the free end of the one ofsaid conductor leads through the passageway for connection to one ofsaid rings;

e. securing the free end of a second of said conductor leads to theother ring; and

f. slidably securing the subassembly comprising the switch rings withleads attached and insulating support member into said housing.

1. The method of uniting a pair of switch rings to an annular insulatingsupport member having a central projection forming a rib portion andthereafter assembling the united parts in a housing containing terminalelements having conductor leads depending therefrom comprising the stepsof: a. providing openings through the rings and rib portion of theinsulating support member; b. supplying adhesive to the parts of thering in engagement with the support member; c. arranging the parts withan adhesive coated switch ring contiguous each side of the rib portionso the openings define a passageway and the switch rings have apredetermined position relative to one another and to the supportmember; d. inserting a pin through said passageway to retain the partsagainst relative movement while the adhesive acquires a set andpermanently secures the switch rings to the support member; e. removingthe pin and thereafter feeding the free end of the one of said conductorleads through the passageway for connection to one of said rings; f.securing the free end of a second of said conductor leads to the otherring; and g. slidably securing the subassembly comprising the switchrings with leads attached and insulating support member into saidhousing.
 2. The method of uniting a pair of switch rings to an annularinsulating support member having a central projection forming a ribportion and thereafter assembling the united parts in a housingcontaining terminal elements having conductor leads depending therefromcomprising the steps of: a. providing openings through the rings and ribportion of the insulating support member; b. arranging the parts withthe switch ring contiguous each side of the rib portion so the openingsdefine a passageway and the switch rings have a predetermined positionrelative to one another and to the support member; c. inserting a pinthrough said passageway to retain the parts against relative movement toassure proper alignment of the parts; d. removing the pin and thereafterfeeding the free end of the one of said conductor leads through thepassageway for connection to one of said rings; e. securing the free endof a second of said conductor leads to the other ring; and f. slidablysecuring the subassembly comprising the switch rings with leads attachedand insulating support member inTo said housing.